The invention relates generally to a method for preparing a beverage, wherein the method comprises the step of heating the beverage in a cup by means of injecting steam into the beverage through a wand and the step of measuring the temperature of the beverage in the cup.
Such a method is known from US-A1-2003/0131735. The known method is performed by a system comprising an elongate frothing wand that includes a generally tubular external sleeve and an inner core within the external sleeve. The inner core defines a steam conduit configured to pass steam from a supply end of the froth wand to an expulsion end of the froth wand configured to eject steam into the beverage. The inner core further includes a coupling mechanism, configured to facilitate connection of the froth wand to a steam supply of beverage preparation device. The coupling mechanism may include threads, clamps, grooves, quick connect mechanisms, or other suitable fasteners complementarily configured to connect with steam supply and allow for easy de-coupling and re-coupling of the frothing wand from the steam supply to facilitate maintenance and cleaning. In addition the external sleeve may be easily removed facilitating cleaning and repair. For example, the external sleeve may be easily removed after a beverage of one flavor is prepared, so as to minimize the risk of imparting an undesired flavor to a subsequently prepared beverage. In addition, several different external sleeves individually configured to accommodate specific functions may be interchangeably coupled to the frothing wand, thus diversifying the utility of the frothing wand. The frothing wand may include a temperature measuring instrument that is positioned near the center of the frothing wand. The temperature-measuring instrument may be a thermometer, thermistor or a thermocouple for measuring the temperature by contact with the frothed beverage. Measured temperatures may be indicated via a visual display and/or other visible or audible mechanism, and may be used to automatically control operation of the beverage preparation device. Although the known system allows for removing the froth wand in order to clean the froth wand, de-coupling and re-coupling of the froth wand including cleaning of the froth wand, in particular the cleaning of the temperature measuring instrument, requires a lot of time. In particular it is desirable from a hygienic point of view that the froth wand is de-coupled, cleaned and re-coupled each time it has been used and this makes the use of such a system somewhat impractical, with the result that users of the system frequently refrain from cleaning the froth wand after it has been used, which could lead to health risks. In addition, a contaminated froth wand may also contaminate the inside of the beverage preparation device, which inside device contamination may be hard to remove. In particular since the temperature measuring instrument comes into contact with the frothed beverage it is prone to contamination and needs thorough cleaning, which is labor intensive in view of its position in the frothing wand.